Protocol

Visualizing Fetal Mouse Vasculature by India Ink Injection

Adapted from Manipulating the Mouse Embryo, 3rd edition, by Andras Nagy, Marina Gertsenstein, Kristina Vintersten, and Richard Behringer. CSHL Press, Cold Spring Harbor, NY, USA, 2003.

INTRODUCTION

The technique described in this protocol was first applied in chicken embryos to visualize the circulatory system. The following method is an adaptation of this "classic" method to the mouse. The basic procedure is to dissect 12.5-dpc (days post-coitus) or older embryos with an intact yolk sac and placenta while the circulation is still active. India ink is then injected slowly into a branch of the vitelline vein of the yolk sac. The carbon particles in the ink are distributed into the arterial system by the beating heart. After fixation and clearing, the three-dimensional structure of the fetal arterial system becomes visible.